Automatic switch.



C. W. EISENMANN. AUTOMATIC swncn, APPLlCATlON FILED APR. 5. 1916.

1,250, 1 52. Patented Dec. 18, 191?.

I formed u on CARI: WILLIAM EISENMANN, OF NEBRASKA CITY, NEBRASKA.

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Specification of Letters Patent.

Patented Dec. 18, 1917.

Application filed April 5, 1916. Serial No. 89,127.

To all whom it may concern:

Be it known that I, CARL W. EISENMANN, a subject of the Emperor of Germany, residing in Nebraska City, Otoe county, State of Nebraska, have invented Automatic switches, of which the following is a. specification. I

My invention relates especially to automatic electric switches deslgned for use in connection with storage battery systems, one of its objects being to provide such an arrangement of contacts of suc a, switch to be subjected to a relatively high voltage at the moment when the switch closes, in order that any non-conductin material adhering to or these contacts and capable of being bro en down by the generator voltage shall be instantly punctured and the electrlcal connection completed between the battery and the generator when their voltages through the switch, in case some non-con- A ducting or insulating material should be v are nearly equal.

Another ob'ect of the invention is to provide an electric switch having main and auxilitary contacts, with means a for certainly preventing said auxiliary contacts from con-- tinuously carrying the main current passing present between the main contacts. a

' These objects and other advantageous ends I secure ashereinafter set forth, reference beinglhad to the accompanying drawings, in

whic

Figures 1 and 2 are diagrammatic representations of two slightly different switches constructed according to my invention; and? Fig. 3 is a fragmentary elevation, to some extent diagrammatic, illustrating the switch contacts in the positlons occupied when the switch is closed.

In the above drawings 1 represents a toragebattery and 2 a generator, the former-being connected to supply current to a line 3-"4. For automatically controlling the charging of the storage battery I provide an electric switch having two pole peace 5 and 6 between which a polarized armature 7 is mounted to oscillate. Said armature for the sake of illustration is shown as having mounted upon but insulated from its contact carrying member 8 supporting a main contact 9 and a pair of auxiliary contacts 10 and 11. Said main contact is placed so as to be capable of electrically connecting a pair of main stationary contacts 12 and 13,

arts as will'cause the main while the auxiliary movable contacts 'aredesigned to be capable of respectively engaging two fixed auxiliary contacts 14 and 15 the arrangement bein such that the contacts 10 and 11 engagesaid contacts 14 and 15 before and disengage them after the main 12 and 13.

The contact carrying arm 8 also provides a flexible or yieldable su port for. a third pair of contacts 16 and I? contact 9 engages or disengages the contacts which are insulated from it and from each other, although they are so mounted that they are capable of I engaging the fixed auxiliary contacts 14 and 15. The arrangement of these two-latter pairs of auxiliary contacts is such that the contacts 16 and 17 respectively engage the fixed contacts 14 and 15 when the switch is open and remain in "such engagement while said switch is being closed until after the contacts 10 and 11 have come into 'engagement with said secondary contacts 14 and 15, r and the contact 9 has engaged the contacts 12 and 13 when they disengage the secondary contacts. Similarly when the switch is moving from its closed to its open position-,rthe'.

contacts 16 and 17 first come into, en

ment with the fixed contacts Hand 15, the main contact 9 then disengages thecontacts 12 and 13, and finally the contacts IOYand 11 disengage the contacts 14 and 15. "The con'-' tacts 13 and 17 of this switch are connected 1 through a conductor 18 with the' positive terminal of the storage battery and a mag- .9 netic winding or coil 19 mounted'on the pole piece 5, is connected between this conductor;

and a conductor 20 leading from the positive terminal of the generator 2, being sojwqund -that it,acts upon the armature 7 to holdthe' switch in its open position. v

A second coil 21, mounted on the ole piece 6, is connected between the positive terminal of the generator 2 and a'conductor.

24 leading to the two contacts 12 and 16 of the switch. being so wound that it acts on the armature 7 to hold the switch closed whenever current is flowing from the generator to the battery, althou h acting to repel said through a conductor 26 and a body of resistance 25 to the negative terminal of the generator, WhlCll 1s directly connected to the negative terminal of the storage battery. This coil 22 is so wound that it attracts the armature 7 when the generator voltage is greater than that of the battery, being assisted by the coil 19 under these conditions.

The coil '23 is connected between the conductor 26, leading from the coil 22 to the resistance 25' and the member 8 with the main contact 9, so that it is energized when the switch is closed at which time it is obviously connected across the line in series with the resistance 25 and manifestly serves to apply full line voltage to any non-conducting material which may lodge between the fixed and movable contacts of the switch. Moreover this coil 23 is wound to neutralize the effect of the coil 22 so that the latter cannot oppose the action of the coil 21 in repelling the armature and opening the switch in case the charging current should reverse by reason of" the generator voltage becomin lower than that of the battery.

nder normal conditions when the voltage in the storage battery is higher than that of the generator or 0t er current source, the line 3-4 is supplied with current from the former and the switch is held open by rear son. of the current flowing from the storage batter through the conductor 18, coil 19 and t rough the generator to the ne ative terminal of said battery; it'being note that by reason of this energization of said coil a magnetic flux is maintained through the pole piece 5 and armature 7 which effectually keeps the latter polarized. If, however, the voltage of the storage battery falls to a predetermined point below that of the generator 2, the reversal of current flow in the coil 19 re els the armature 7, thus closing the switch. The flow of current from the generator 2 through the conductor 20,

coil 21, conductor 24, switch contacts 12, 9 and 13 and conductor 18, then causes said coil 21 to hold the armature 7 in its position adjacent the pole piece 6, in which the switch is closed, so that a charging current is delivered to the storage battery. It is to be noted that when the auxiliary contacts 10 and 11 first come into engagement with the contacts 14 and 15 as the switch is being closed, the full generator voltage exists between the contacts 14 and 10 so as to in-' stantly break down any non-conducting film or puncture any insulating substance which would interfere with their good electrical connection and'which is capable of bein broken down by such voltage, since throug the conducter 20, coil 21, conductor 24 and contact 16, the contact. 14. is. connected to the positive generator terminal while the contact 10' through the cross bar 8, coil 23, conductor 26, and resistance 25 is likewise connected to the negative terminal of the generator. Thereafter in closing the switch, the main contact 9 electrically connects the there should be an insulating or non-conmain stationary contacts 12 and 13 and finally the contacts 16 and 17 disengage the contacts 14 and 15,- thus cutting off the secondary contacts 10 and 11. If therefore ducting bod or film between the main contact 9 and t e contacts 12 and 13. this similarly would be exposed to the full generator voltage as in the case of the auxiliar contacts above noted with the result t at it would be instantly punctured.

By the above described means I insure the instantaneous electrical connection of the generator'to the storage battery at the time the switch closes, thus preventing the injurious rush of current which would otherwise occur in case the insulating film or body prevented current flow between the contacts of the switch when these were first en aged and thus allowed the generator vo tage to rise considerably above that of the storage battery.

Moreover by the use of the tertiar movable contacts 16 and 17', I effectual y prevent the secondary contacts 10 and 11 from being compelled to carry the full current after the switch has been completely closed as might otherwise occur in case imperfect contact was made between the contact 9 and the fixed contacts 12 and 13 ;-it being understood that the mounting of the contacts 10 and 11 as well as that of the contacts 16 and 17 is preferably made of flexible or sprin material which permits of the above descrl ed action of the switch, thou h obviously the same end mi ht be secured 1y other means without departing from my invention.

In the system illustrated in Fig. 2 I omit the resistance 25 and the coil 23, connecting a condenser 28 between the member 8 of the switch and the negative terminals of the battery and generator. With such an arrangement of parts on closing the switch a spark is formed at the contacts due to the discharge of the condenser which thus punctures or breaks down any non-conducting material between the main contacts and secures the same result as that accomplished by the combination of Fig. 1, there bein no spark at the opening of the switch. his particular form of the invention is to be preferred in some cases, since there is obviouslyno current flow through the condenser under operating conditions.

I claim I v 1. The combination of a storage battery; a generator; an electric switch for connectplying substantially the full line voltage to tire cmtacts of the switch at the time it is c ose ihg the battery and generator when the former 1s to be charged; and. means for ap- 2. The combination of a generator; at storage battery; an electric switch for connecting said generator and battery when the lat- 13c ter is to be charged, and including main and auxiliary contacts; with means for puncturing any insulating material between the main contacts at the time the switch is closed.

3. The combination of a generator; a storage battery; and an automatic switch for connecting the battery to the generator when the former is to be charged; with means for automatically puncturing any insulating material between the switch contacts at the moment of closing the switch to insure the instantaneous flow of current from the generator to the battery.

4. The combination of a generator; a storage battery; and an automatic switch for connecting the battery to the generator when the former is, to be charged; with means for automatically puncturing any-insulating maage is greater than that of the main portion thereof; and a condenser in said branch circuit CARL v WILLIAM EISENMANN. 

